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[AMPS] 4-1000

To: <amps@contesting.com>
Subject: [AMPS] 4-1000
From: Peter.Chadwick@gpsemi.com (Peter Chadwick)
Date: Fri, 18 Jul 1997 09:22:00 +0100
Lane,

Are you looking to run these guys as a linear, or as plate modulated am?

If the latter, then you'll be pushing the vacuum variables if you run
5KV on the plates, since at full modulation, the plate volts hits 10KV.

If you run it as a linear, then you'll only get about 1KW to 1.2KW of
carrier - the PEP is 4 times the carrier for AM.

If you are plate modulating,(and running, I guess Class C) then getting
the screen supply from the plate by a dropping resistor is probabaly the
best approach, unless you can get a modulation xfmr with an extra
winding for the screen. For plate and screen modulation, you'll need  a
hefty mod. xfmr., and a modulator capable of 2500 watts or so of audio.

Straight screen or grid modulation is another approach. They're more
tricky to set up, and usually run about 30% efficiency on the carrier,
but need less audio.

In Class C, plate modulated, a pair of 4-1000's will run 2780 watts
carrier output, which with plate and screen modulation will be 11.12KW
PEP. That needs 3KV on the plate at 1.2Amps, and 500 volts at 290mA for
the screens.

As a linear, grid driven AB2, you'll get 3KW PEP, or 750watts of carrier
if you 100% modulate. That needs
4KV on the plates at 2.4Amps peak, and 500 volts on the screens, peaking
190mA.

Depends on how you're doing the AM.

73

Peter G3RZP

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